#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int howManyGames(int p, int d, int m, int s) {
    // Return the number of games you can buy
    int count=0,i,cost,sum=p;
    for(i=p;i>=m;i=p-d)
    {
        cost=p-d;
        sum=sum+i;
        if(cost<=s)
        {
            count++;
            p=i;
        }
    }
    for(i=p;i>=0;i=p-d)
    {
        cost=p-d;
        sum=sum+m;
        if(sum<=s)
        {
            count++;
            p=i;
        }
    }
    return count;
}

int main() {
    int p; 
    int d; 
    int m; 
    int s; 
    scanf("%i %i %i %i", &p, &d, &m, &s);
    int answer = howManyGames(p, d, m, s);
    printf("%d\n", answer);
    return 0;
}